--- shadow-4.1.2.1/libmisc/xmalloc.c	2008-08-30 21:55:44.000000000 -0500
+++ shadow-4.1.2.1/libmisc/xmalloc.c.new	2008-08-30 21:55:36.000000000 -0500
@@ -61,5 +61,6 @@
 
 char *xstrdup (const char *str)
 {
+	if(str == NULL) return NULL;
 	return strcpy (xmalloc (strlen (str) + 1), str);
 }
